Lives and Opinions of Eminent Philosophers

​And Diogenes the Epicurean also says this in the first book of the Selected Opinions.] "Furthermore, the regularity of a period should be conceived just as some ordinary occurrences take place among us too; and divine nature must not be brought in to account for these things in any way, but must be preserved free from service and in complete blessedness. For if this is not done, the whole explanation of celestial phenomena will be futile, just as has already happened to some who did not grasp a possible method, but fell into futility by supposing that it comes to be in only one way, and rejecting all the other ways that accord with possibility, being swept away into the unthinkable and unable to contemplate together the phenomena, which one must receive as signs.

"The variations in the lengths of nights and days can also occur on account of the sun's movements becoming fast and again slow above the earth, on account of the varying lengths of places and its traversing certain places more quickly or more slowly, just as certain things are observed among us too, in agreement with which one must speak concerning celestial matters. But those who grasp the single explanation fight against the phenomena and have fallen away from the way in which it is possible for a human being to observe. "Weather signs can occur both by coincidences of seasons, just as among the animals visible among us, and on account of alterations and changes of the air. For neither of these conflicts with the phenomena;

​but in which cases it comes to be on account of this or that cause, it is not possible to discern. "Clouds can come to be and be formed both by compressions of air through the driving of winds, and by the entanglements of mutually grasping atoms that are suitable for bringing this about, and by the collection of streams from both earth and waters; and in many other ways it is not impossible for the formations of such things to be brought to completion. And from them already, in one way being squeezed and in another changing, waters can be brought to completion,

​and furthermore by the conveyance through the air of streams moving from suitable regions, when a more violent downpour arises from certain accumulations suitable for such discharges. Thunder admits of coming to be both by the winding of wind in the hollows of clouds, just as in our vessels, and on account of the rumbling of fire charged with wind in them, and also by ruptures and separations of clouds, and by collisions and fractures of clouds that have taken on a crystalline coagulation. And in general, the phenomena demand that one say that this department too comes to be in multiple ways.

"And lightnings likewise come to be in multiple ways; for both by the friction and collision of clouds the conformation that produces fire slips out and generates lightning; and by the blowing out from the clouds by winds of such bodies as provide this brightness, and by squeezing, when compression of the clouds takes place, whether by one another or by winds; and also by the entrapment of light scattered down from the stars, which is then driven together by the motion of both clouds and winds and bursts out through the clouds; or by the filtration through the clouds of the finest-particled light, [in the way clouds are ignited by fire and thunders are brought to completion] and by the motion of this; and by the inflammation of the wind arising both through the intensity of its motion and through violent compression;

​and also by the ruptures of clouds by winds and the fallout of atoms productive of fire, which produce the appearance of lightning. And in many other ways it will be easy to discern for one who always clings to the phenomena and is able to contemplate together what is similar to them. And lightning precedes thunder in such a condition of clouds both because the conformation productive of lightning is expelled at the same time the wind strikes in, while later the wind winding about produces this rumbling; and also, when both strike together, because lightning makes use of a more intense speed toward us, while thunder lags behind,"